Rock-reamer for drill-heads.



I. P. KARNS. ROCK REAMER FOR DRILL HEADS.

APPLICATION FILED MAR- 28.19I3.v l I Patented @et I2, 1.915.

mm-LN,

Atto rri eys.,

JOHN yP. minus, or BOULDER, ,f coLoRADo,1 AssiGr-Tonif'rofir.'if:- KARNs 'rollin-Ennio MACHINE co., orizc'mnnnn, .coLoRnDoQ- i @examinaron minivan-irs,.-

To-aZZ whom t may concern:- 4 Be it know'n that-I, JOHN P. KARNS, a citizen of the United States, residing at Boulder, inthe county of Boulder and 'State of Colorado, have invented'- anew and useyful Rock-Beamer for Drill-Heads,jof which the followingisa specification.y

The present.y inventicn'r"relatesl to. improve-A ments in rockreamerjs 'for 'drill' heads, the' same, being applicable todrill heads Vof-,vari-4 ous sizes, one object or the-present invention` being theprovision of a. drill head inwhich' one, or more, of the reamers is' so mounted--l as tol avoid lrict'i'ong-with thebore Iduring retraction and advance andwhich willbe" automatically' moved-laterally when in con tact with the header of the bore. s

A further object 4of the' present invention is the provis'ion'of a reamer for'fdrill headsv wherein the drill head, is provided with one yor more radially disposed pivotally mountv ed reamingv cutters, there being provided means for retracting it, when Vout-.of contact or not under pressure, the working position of the' same being caused by ablow against the header v of thel bore, such. blow causing the reamer to be yprojected laterally and firmly locked against radial movement during the reciprocation and slight rotation of the drill head, 'thusreaming the bore so that the fixed cutters will have ample space to be movedba'ck and forth. without frictio-nal y contact with the walls of the bore.

With the foregoing and vother objects in view whichwill 'appear as the description proceeds, the. invention resides in thev combination and arrangement-of parts yand in the details of construction'hereinafter described'. and claimed, it being understood that changes in the precise embodiment of the invention herein disclosed can be made withlin the scope of what is claimed without de-I parting from the spirit of the invention.'

In the drawings, Figure 1 `is a transverse sectional view vthrough a 'drill head constructed according to and embodying the present invention, the parts being inthel position they assume'when the head is pro- 'jected forward yand cutting. Fig. 2 1s a.'

similar View withthe parts in the position they assume upon its withdrawal'or retractingstroke`. Fig. 3. isan end elevation ofthe headequipped with a yplurality of cutters, Fig. 4 is a detail perspective View lof one of the pivoted cutters.

' ing to the Size the ldan head'.

openingslli for the engagementtherewithof the .retaining bolts 5.- l

In the` form shown in Fig. a plurality* of4 the cutter's are employed, butfth'esec'utv specification of Letters' ina'cira.l "PmjentQ-doct, 12,1915.- Appnatianjied march 2s, 1913: serial np. 757,451? i? V- i Referring to .the drawings, thenurn'einl 1 i .60 cutters 3,these cutters being provided withV ters aliento be ,increased` or decreased -accord-y f .In orderrto'providea means to permit fof the proper attachingof thev head upon the'.

retractive .stroke and also to permit of the proper vprojection of thefcutters to perform the` cutting workI during the drilling iop'eration`,-recesses Gare provided radially in thev enlarged portion 1a of the head, the walls 7" `being 'disposed l at an acute angle'tothe wally7 thereof and having led radially therefrom ladjacent the inner portion thereof, a cylin.- difical bore or socketv 8.

Thel @naar 9, provided with the Cylindical holes l10,` is disposed to fit within the recess or slot V6 and be held against displacement from the head 1` by means of the pin 11, said pin 11 being of lesser diameter than theaperture'or opening 10,' so that the cutter -9 is permitted therelative movements, yas clearly shown in Figs. 1 and 2.

A' spring' 12 ,is disposed in the socket 8, `and bearsagainst the edge 14 of the cutter 9 and' lunder normal conditions pulls the cutter in the position,l as shown in Flg. 2,

the edge 13 of the cutter. being provided v withl the foreshortened portion 13 so that "the cutterf9. is disposed to l,assume the positions as shown -in Figs. 2 and 1, and thus be locked in proper relation'within the slot 6. The angular edge'14 is: of the necessary anglefor'in'clination to t (zo-extensively with the wall-7 ofthe recess 6 so that when the tion 'as showny in gFig. 1, the cutterwill assume the position therein and thus asslst in reaming-the-bore, the .retracted movement of the'head 1 due to the release of the cut.

, head 1 strikes, with the parts in the positingportions 15 and 16 from-the wall vof the bore, permitting the spring 12 to act upon the inner end of the cutter 9 to move it from the position as shown in Fig. 1 to that shown in Fi 2, thus reducing the diameter of the dril head, or in other words vpermitting a slightco1lapsing thereof so that the retracted movement will in noA way 'be retarded,v due to the rictional engagement of the teeth l with thelwall of the bore. lit is also apparent that with this construction, the drill head maybe readily causing the cutter to be moved from the position as shown in FigfQ to ythat shown in; Fig. l andthus throwing the reaming teeth into engagement with PIthe wall of the bore adjacent theV end thereof. By this 'means the pivoted resiliently supported cutters 9 will cut the wall of the bore adjacent the end thereof whilethe teeth oi? the cutter bodily and eccentrioally movable `about a 3 will act primarily upon 'the end, Y

lit will Ithus be seen that the reamerihas two striking surfaces of steel points, one of to increase the diameter of the borev `for the easy movement of Athe drill head. By

' mounting the reamer or cutter upon the pin,

the' pin forms a pivot therefor when not under' a blow, and does not receive the eect of the blow when the cutter is moved from released top impact position, theicavity or recess in which the reamer is mounted being y especially designed for this purpose.' .llt will 35 also`be` noted that the spring is' soppositioried lat one side of the cavity 'as to press against the inner `side 'of the' reamfer below the pin, thus pushing thepointed surface f ofthe reamer that strikes the wall ofthel 4.0

tunnel away therefrom, holding the same advance or the regular cutting points ci"v the driil head.` By this action, the header lengaging cutting points ot the reamer'will maaier engage the header of theftunnel slightly-iii advance of the regular 'cutting points of the drill head, and the' other cutting points thereof will be thrown into' contact with the side wall 'of the tunnel so that-the lWall at such point willbe chipped to enlargethe tunnel diameter and thus-permit free action 'ot the drill head at all times.

y lVhat is claimed is:AY f p l. in a device of 'the class described, a

reamer mounted on thehead and including ,a front cutting edge andA a side cutting' edge,

of the cutter and operating by impact to larly disposed edges which contact simulhead; an end cutter carried thereby; and 'a' 6o one corner ofthe reamer beingin advance move both of the cutting edges oithe reamer .to active positions, the reamer having angutaneously -with the head to support the f y reamervin activeposition, the reamer'being ixed. point to eect a shifting of the reamer..

2. lin 'a device of the class described, a

. Ihead; an endv cutter 1 on the'head'; and a y reamerinounted on the head andincluding i; f.

a front cutting edge and va; '/sidecutting'edge,

one corner of the reamer heingin advance of v Vthe cutter and operating by impact-to move both of the cutting edges-ofthevreamerfgto active position, the reamer having 'ang'fularly disposedtran'sverse and longitudinal edges, the longitudinal' edge: engaging the head to and the transverse ed eengaging the head to hold the cutting e ges in, inactive position, the reamer being bodily and eccentrif cally movable about a jxed; pointflto 'egdect coacting with the reamertoshittthesaine1 hold the' .cutting e s in` active position,

a shitting 'f the reamer; and` spring means to inactive position. g

ln testimony thatfclaim the foregoing y as my own, l have heretoc'ained my signan ture in the presence of two witnesses.

"Witnesses: i.

SHIRLEY Davis; 

